Win7 USB error ==> Fixed in SVN

I upgraded from VirtualBox 4.0.x (latest version of 4.0 series) to the latest version of 4.1 on Windows 7 Ultimate x64. When I go into any VirtualBox machine settings, I get and error window that says:

Failed to access the USB subsystem.

Could not load the Host USB Proxy Service
(VERR_FILE_NOT_FOUND). The service might not be
installed on the host computer.

Here's a link to the only VBox.log that may have some info, because the error only shows up either when I'm entering VirtualBox machine settings before I start it, or when I enter the settings while the machine is running. I don't know if it'll have any info, but here it is:

Change History

VBox 4.1 behaves more consistent wrt to host USB device handling, i.e. it will display such message whenever it detects it won't be able to perform USB device capturing for any reason.
Despite that you were not seeing this message and was able to list USB devices in VBox pre-4.1, were you able to attach any USB device to guest?

VBox 4.1 behaves more consistent wrt to host USB device handling, i.e. it will display such message whenever it detects it won't be able to perform USB device capturing for any reason.
Despite that you were not seeing this message and was able to list USB devices in VBox pre-4.1, were you able to attach any USB device to guest?

Yeah, I was previously able to attach my USB keyboard, just for experimentation. I think I also attached my printer.

Replying to shark.basketball: I'm unable to reproduce your "VERR_FILE_NOT_FOUND" problem here. I can post you an instrumented build with verbose logging enabled so that you can collect and post us back the debug log for VBox USB subsystem initialization. If you are willing to test, just drop me a mail at mikhail dot sennikovsky at oracle dot com I then post you a link to the build and instructions on how to collect the log.

I have the same error message when I try to use the new version of virtual box (4.1.0). I did not have this error on the latest version 4.0.12. I’m using Windows 7 home premium 64.
I have installed the new oracle extension packages too.

The error message is :

Failed to access the USB subsystem.
Could not load the USB Proxy service (VERR_FILE_NOT_FOUND).
The service might not be installed on the host computer.

Replying to amiri: same question as to everyone here: were you able to attach USB devices to a VM with VBox 4.0.x ? If not - then this is not a regression, just a more strict and consistent way of err handling.

Replying to amiri: same question as to everyone here: were you able to attach USB devices to a VM with VBox 4.0.x ? If not - then this is not a regression, just a more strict and consistent way of err handling.

Previously I didn't try to attache a USB to my guest system in my windows host (& I didn't get any errors on each machine settings), to give a correct answer to your question I uninstalled the new version and installed the older version again. With in Virtual Box 4.0.12, I can see my USB devices like my flash USB disk and etc but I can not attache them. For example I tried to attache my USB flash drive & I got the following error:

Just a data point, I was having the same issue but thanks to misha's assistance I found that it was caused by some USB logging software I had installed (HHD Device Monitoring Studio). I've uninstalled DMS for now. Hopefully DMS and VB will play nicely sometime in the future, because DMS is very useful.

After installation of VM 4.1 I found following issues what didn't appear earlier and were not resolved by ver. 4.1.2:
1) error with Host USB Proxy Service (VERR_FILE_NOT_FOUND),
2) bridged networking not functioning,
3) shared folders inaccessibles.

To all having VERR_FILE_NOT_FOUND issue on Windows hosts: Please try this test build that contains a fix for this issue and let me know whether it fixes the issue for you.
Besides that the "VERR_FILE_NOT_FOUND" dialog should not appear now, device capturing should work as well (unlike pre-4.1), so please test whether you can attach any USB devices to VMs as well.

I can confirm that this fixes the problem. I now do not get the error popup when entering settings, and have successfully attached USB devices to virtual machines. Is this going to be fixed in the next public release as well?

The test build still doesn't work with HHD Software USB Monitor installed. That's with the test build's guest additions installed and 4.1.2 extension pack. Sounds like you've made some other people happy though!

The test build still doesn't work with HHD Software USB Monitor installed. That's with the test build's guest additions installed and 4.1.2 extension pack. Sounds like you've made some other people happy though!

What do you mean by "with the test build's guest additions installed"? You need to install test build on host, guest additions, should not matter since its a purely host side problem.
Did you install the test build on host?

The test build still doesn't work with HHD Software USB Monitor installed. That's with the test build's guest additions installed and 4.1.2 extension pack. Sounds like you've made some other people happy though!

What do you mean by "with the test build's guest additions installed"? You need to install test build on host, guest additions, should not matter since its a purely host side problem.
Did you install the test build on host?

Woah! OK, so now it's working. I _think_ that what I did was: uninstall DMS, install VB (test build), run VB and add a device, install DMS, run VB and add a device -> success. It certainly did not work when I installed DMS before VB.

There's something odd here. Perhaps the best thing would be for you to leave it and I'll do some more testing to see if I can isolate the exact sequence that doesn't work.

I uninstalled VB and DMS. Manually removed items the uninstallations didn't, such as extension packs and drivers. Rebooted. Installed DMS, used it to capture some traffic. Installed VB, attached a couple of devices, everything worked fine.
That's not what I expected! I must admit I'm out of ideas about how to make it fail again. I was extremely careful with the last testing I did (comment 22, above) so I know it really _did_ fail, but maybe that was just some sort of crud buildup in my PC that got cleared by the uninstall/install cycles I did?

Replying to RobBrownNZ: I wonder if this was caused by VBox USBMon driver not being updated in your previous install that did not work for you.
In any way glad to hear it works ok now. Let me know if you see this issue again.

To all having VERR_FILE_NOT_FOUND issue on Windows hosts: Please try this test build that contains a fix for this issue and let me know whether it fixes the issue for you.
Besides that the "VERR_FILE_NOT_FOUND" dialog should not appear now, device capturing should work as well (unlike pre-4.1), so please test whether you can attach any USB devices to VMs as well.

Thanks a lot! The fix helped to resolve most of issues. USB devices are discovered, sharing folders work.

Problems with network connections were not resolved. External Internet connection works only at selection of virtual connection adapter (NAT mode) and its not possible to access shared folders then. Optiom of bridged WiFi networking works fine for Shared folders (home network is accessible) but it doesn't enable Internet connection. In current state of arts I have to switch between the 2 kinds of adapters (when both adapters are turned on only one is actually active). Is it problem with my computer configuration?

To all having VERR_FILE_NOT_FOUND issue on Windows hosts: Please try this test build that contains a fix for this issue and let me know whether it fixes the issue for you.
Besides that the "VERR_FILE_NOT_FOUND" dialog should not appear now, device capturing should work as well (unlike pre-4.1), so please test whether you can attach any USB devices to VMs as well.

Hi,
the link doesn't exist any more. Is there an other build available to test the "solved" USB issue?
TIA